Vehicle accelerator linkage assembly

ABSTRACT

A cable-type vehicle accelerator linkage connects the conventional vehicle accelerator pedal to a carburetor throttle valve, the cable being surrounded by a variable length, expandable-contractible linkage means including a compression spring to urge the linkage parts apart so that the accelerator pedal and throttle valve are always biased in a direction toward engine idle speed position; breakage of the spring providing no interruption to the biasing force but merely multiplying the number of springs operating in series.

United States Patent Reno [ 51 Mar. 7, 1972 [54] VEHICLE ACCELERATOR LINKAGE ASSEMBLY [72] Inventor: Frederick Reno, Detroit, Mich. I [73] Assignee: Ford Motor Company, Dearbom, Mich.

[22] Filed: June 2, 1970 [2l] Appl. No.: 42,644

[52] US. (I 74/513 [51] Int. Cl. ..Fl6c 1/10 [58] Field oiSearch ..74/5l3,501,501.5, 108

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 798,513 5/1936 France ..74/513 963,979 7/1964 Great Britain ..74/5 13 Primary Examiner-Milton Kaufman Assistant Examiner--F. D. Shoemaker Attorney-John R. Faulkner and Robert E. McCollum [5 7] ABSTRACT A cable-type vehicle accelerator linkage connects the conventional vehicle accelerator pedal to a carburetor throttle valve, the cable being surrounded by a variable length, expandablecontractible linkage means including a compression spring to urge the linkage pans apart so that the accelerator pedal and throttle valve are always biased in a direction toward engine idle speed position; breakage of the spring providing no interruption to the biasing force but merely multiplying the number of springs operating in series.

5 Claims, 3 Drawing Figures VEHICLE ACCELERATOR LINKAGE ASSEMBLY This invention relates, in general, to an internal combustion engine for a motor vehicle. More particularly, it relates to the accelerator linkage connecting the vehicle accelerator pedal to the engine carburetor throttle valve.

Many of the present day motor vehicles have accelerator linkage assemblies consisting of a flexible cable between the vehicle accelerator pedal and the carburetor throttle valve. Since the latter operates only in tension, release of the accelerator pedal, or manually pulling up on the accelerator pedal, will not per se return the carburetor throttle valve to a position other than that already attained. Therefore, such a system generally has a tension spring hooked between a stationary portion of the vehicle and some portion of the accelerator cable to positively exert a force that not only will return the carburetor throttle valve to its engine idle speed position, but also move the accelerator pedal to its closed throttle position.

The use of a tension return spring in such asystem generally is a logical choice; first, because of its ease of installation and location in that it can be connected to any convenient stationary portion of the engine or vehicle with its opposite end hooked over any portion of the accelerator linkage. Secondly, it is easy to change springs if the particular accelerator pedal effort, for example, is too high or too low, simply by removing the hooked portions.

It will be clear at once, however, that if a failure occurs in the tension spring, the condition described above occurs; namely, the carburetor throttle valve will remain in the position attained and the vehicle speed will be as it was before breakage of the spring. This can result in an uncomfortable driving condition.

The invention, therefore, is directed to a vehicle accelerator linkage assembly that is essentially fail-safe in operation and eliminates the above disadvantages of the conventional tension spring biasing force described. More particularly, the invention relates to an accelerator linkage assembly that includes a variable length link, or expandable-contractible link, between the carburetor throttle valve and a stationary reaction member, in which a compression spring is installed in such a manner as to always bias the carburetor throttle valve to its engine idle speed position and the vehicle accelerator pedal to a corresponding closed throttle position.

It will become clear at once that should failure occur in the spring, as by breakage, for example, the operation of the spring is affected by degree or magnitude only since the previous single spring then merely becomes a plurality of springs while still maintaining its compressive biasing force. Release of the accelerator pedal still permits the multipart spring to expand the variable length link to close the carburetor throttle valve. No interruption occurs, therefore, in the return operation of the linkage assembly to move the accelerator pedal and carburetor throttle valve to rest positions.

It is a primary object of the invention, therefore, to provide a vehicle accelerator linkage assembly that is essentially failsafe in operation to provide a biasing force that urges the carburetor throttle valve toward an engine idle speed position at all times.

Other objects, features and advantages of the invention will become more apparent upon reference to the succeeding detailed description thereof, and t the drawings illustrating a preferred embodiment thereof; wherein,

FIG. I shows, isometrically, an elevational view of a vehicle accelerator linkage assembly embodying the invention;

FIG. 2 is a cross-sectional view of a portion of the FIG. 1 showing; and,

FIG. 3 is a cross-sectional view of a detail.

FIG. 1 shows the accelerator linkage assembly of the invention including a conventional vehicle accelerator pedal 14 pivotally mounted by a U-shaped yoke member 16 on the lower end 18 of a bellcrank-type lever 20. The pedal includes a return spring 21 that urges the pedal to an upright attitude.

Lever 20 is pivotally mounted at its fulcrum point 22 to a mounting bracket 24 that would be fixed by rivets or other suitable means, not shown, to the vehicle firewall, not shown. The upper arm 28 of lever 20 has at its end a pivotal connection 30 to one end of a flexible cable 32 that transmits force in tension only. The opposite end of cable 32 is secured, in a manner to be described more fully later, to the upper end 36 of a conventional carburetor throttle lever 38. The latter is fixedly secured on an extension 40 of the carburetor throttle valve shaft. The throttle shaft in turn is pivotally mounted on a stationary portion of the throttle body, not shown.

It will be clear, as thus far described, therefore, that depression of the accelerator pedal 14 in a counterclockwise direction willrotate the lever 20 in a clockwise direction to place the cable 32 in tension and pull the throttle valve lever 38 in a rightward direction to increase the speed of the engine.

Referring now to FIGS. 2 and 3, cable 32 is slidably mounted in a flexible polypropylene sheath or housing 41 that is fixed at opposite ends within attaching steel sleeve mounting brackets 42 and 43. The bracket 42 including a mounting pad 44 having an integral sleeve boss 46. The end of sheath 41 would be crimped within sleeve 46. The pad 44 would be screwed to the engine firewall, not shown.

FIG. 3 shows bracket 43 as also including a mounting pad 47 with a sleeve 48 projecting from one side and a flanged sleeve 49 projecting from the other. The flange and pad define a neck portion 50 between a pair of shoulders that fits in the slot 51 of a mounting member 52. The latter would be screwed or otherwise secured to a portion of the engine, such as the valve train cover. The sleeve 48 would be crimped to retain sheath 41 therein.

At the carburetor end, cable 32 passes through and is fixedly attached to a metal adapter 53 having a ball socket 54 and a clip 55 that frictionally slips over a protruding ball stud 56 projecting from carburetor throttle lever 38 (FIG. I). Adapter 53, in this case, is crimped or otherwise secured in the end portion of a sleeve 58 having a flanged end 60. Slidably mounted in a telescoping or nestable manner within sleeve 58 is a second sleeve 62 encompassing sheath 4! and also having a flange end 64. Operably seated between flanges 60 and 64 and surrounding sleeve 62 is a compression spring 66 of a predetermined preload sufficient to bias the tube parts 58 and 62 apart, in the manner shown.

Flange 64 of sleeve 62, in this case, is biased against the stationary bracket shoulder 49 to provide reaction for the spring force.

Flexible cable 32 passes through the bracket member 43 and through the sleeves 62 and 58 to its attachment at the end portion 53. Cable 32 is thus surrounded coaxially by sleeve portions 58 and 62.

It will be clear from the above that spring 66 provides a suitable biasing force to normally maintain sleeves 58 and 62 biased apart to the positions shown in FIGS. 1 and 2, and that depression of the accelerator pedal 14 from its engine idle speed position shown will rock lever 20 in a clockwise direction to place cable 32 in tension and pull the same toward the right in FIG. 2. This will provide a unitary movement of sleeve 58 and cable 32 toward the right causing flange 60 to compress spring 66, with sleeve 62 sliding telescopically into sleeve 58. This will cause a clockwise rotation of throttle lever 38 to open the throttle valve in the desired manner.

It will be clear, of course, that should a failure, by breakage, for example, of spring 66 occur, substantially no interruption to action is provided since any breakage in spring 66 merely provides a plurality of spring parts still operating in series in compression to provide the desired return action. Release of the accelerator pedal 14 will immediately permit the force of compression spring 66 to return the sleeve 58 to its normal at rest position closing the throttle valve to its engine idle speed position and simultaneously moving the cable 32 to the left in FIG. 2 to return the accelerator pedal 14 to its idle speed position.

From the above, it will be seen that the invention provides a fail-safe accelerator linkage assembly insofar as the biasing force is concerned.

lclaim:

1. An engine accelerator linkage assembly comprising, a flexible tension transmitting cable operably connected at one end to a foot-operated accelerator pedal means and at its other end to a carburetor throttle valve lever pivotally movable toward and away from an engine idle speed position, a stationary force reaction member supported on a portion of said engine, and expandable-contractible means fixed to said cable and located between said carburetor throttle valve lever and said reaction member and having a plurality of parts, and compression spring means between said parts biasing said parts apart and said throttle valve lever towards an engine idle speed position whereupon movement of said pedal means in a direction to increase engine speed moves said cable in tension to contract said parts by compression of said spring means and to open said throttle valve lever, release of said accelerator pedal means permitting return of said throttle valve lever to an engine idle speed position by expansion of said parts by said compression spring means.

2. An assembly as in claim 1, said parts comprising a pair of sleeves nestable one within the other and each having flange means on corresponding ends, said spring means being seated between said flange means.

3. An assembly as in claim 1, said expandable-contractible means comprising a variable length link having telescoping arts. p 4. An assembly as in claim 3, said parts being coaxially slidable mounted with respect to said cable.

5. An assembly as in claim 3, said spring means being seatable between and on corresponding end portions of said parts.

i i i i i 

1. An engine accelerator linkage assembly comprising, a flexible tension transmitting cable operably connected at one end to a foot-operated accelerator pedal means and at its other end to a carburetor throttle valve lever pivotally movable toward and away from an engine idle speed position, a stationary force reaction member supported on a portion of said engine, and expandablecontractible means fixed to said cable and located between said carburetor throttle valve lever and said reaction member and having a plurality of parts, and compression spring means between said parts biasing said parts apart and said throttle valve lever towards an engine idle speed position whereupon movement of said pedal means in a direction to increase engine speed moves said cable in tension to contract said parts by compression of said spring means and to open said throttle valve lever, release of said accelerator pedal means permitting return of said throttle valve lever to an engine idle speed position by expansion of said parts by said compression spring means.
 2. An assembly as in claim 1, said parts comprising a pair of sleeves nestable one within the other and each having flange means on corresponding ends, said spring means being seated between said flange means.
 3. An assembly as in claim 1, said expandable-contractible means comprising a variable length link having telescoping parts.
 4. An assembly as in claim 3, said parts being coaxially slidable mounted with respect to said cable.
 5. An assembly as in claim 3, said spring means being seatable between and on corresponding end portions of said parts. 